stabilizer
Stabilizers yog "intentionally additives" siv los tiv thaiv polymers los ntawm ib puag ncig influences (kub, UV teeb, thiab lwm yam). Lawv raug ntxiv rau cov yas los tiv thaiv cov polymer los ntawm thermal (thermal), UV thiab mechanical degradation thaum ua thiab siv. Lawv ua raws li antioxidants, thermal (thermal) thiab lub teeb / lub teeb (UV) stabilizers, nplaim retardants / nplaim retardants thiab oxygen scavengers. Rau PVC, lub thermal decomposition kub yog ze rau cov txheej txheem kub, yog li kev siv cov cua sov kom tsim nyog thaum lub sij hawm thiab tom qab nws ua yog qhov tseem ceeb.
Qee cov stabilizers yuav muaj qee cov hlau hnyav lossis lawv cov ions (xws li stabilizers rau PVC qhov rai profiles thiab cov kav dej feem ntau yog cov hlau lead lossis barium, cadmium lossis zinc compounds, ntxiv rau organo-nickel compounds yog siv tshwj xeeb rau UV stabilization), uas tuaj yeem ua rau muaj kev phom sij rau kev noj qab haus huv.
Lub ntsiab thermal stabilizers muaj rau PVC yog:
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Lead compounds (tsuas yog cov hlau lead sulfate thiab lead stearate). Txhua hom hlau lead yog cov tshuaj lom neeg heev rau tib neeg vim lawv cov kev cuam tshuam loj heev. Cov kev tshawb fawb pom tau hais tias cov hmoov lead tuaj yeem ua rau lub hlwb puas, kev kawm tsis taus, ntshav siab thiab txawm tias nchuav menyuam. Tshwj xeeb tshaj yog rau cov dej uas muaj cov hmoov lead-contaminated yog ib qho teeb meem loj uas muaj teeb meem loj rau kev noj qab haus huv. Thaum noj los ntawm lub plab zom mov, cov hlau lead tuaj yeem nkag mus rau hauv lub cev thiab cov pob txha, nws thiaj li ua rau ntau yam kab mob xws li ntshav ntshav mus rau kev puas hlwb (Godwin, 2001). LEEJ TWG pom zoo kom muaj cov hmoov txhuas ntawm 10 ug / l hauv cov dej haus (WHO, 2006).
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Organotin tebchaw feem ntau suav nrog monobutyltin (MBT), dibutyltin (DBT) thiab tributyltin (TBT). Tsis tas li ntawd, dimethyltin (DMT), lwm organotin pom nyob rau hauv cov khoom siv dej hauv tsev, tshwm sim los ntawm cov khoom siv stabilizers siv hauv PVC thiab chlorinated PVC (CPVC) cov khoom (Ehman li al., 2007). Nws tau raug xav tias cov tshuaj organotin tuaj yeem ua rau tsis tu ncua thiab muaj tshuaj lom rau hauv nruab nrab paj hlwb thiab lub cev tiv thaiv kab mob, nrog rau lub siab (Korgiesen and Rice, 1998). Organotin compounds suav txog kwv yees li 9.3 feem pua ntawm European stabilizer noj (CEC, 2000).
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Cadmium (Cd) thiab nws txoj kev ntsev ntsev. Cd yog ib qho tshuaj lom nyob rau hauv cov npe ntawm 10 cov pa phem phem tshaj plaws ntawm United Nations Environment Program; Nws tuaj yeem ua rau lub raum puas thiab ntshav ntshav, thiab ib zaug nqus tau, nws tuaj yeem nyob hauv tib neeg lub cev rau 30 xyoo. Kev nqus pa ntawm cadmium oxide fumes yog qhov phom sij loj tshaj plaws, nrog rau ntau qhov ua rau tuag taus.
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Antimony (Sb) yog siv hauv PVC los txhim kho cov nplaim hluav taws kub nyhiab ntawm cov tshuaj chlorine.
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Organochlorines feem ntau yuav tsum tau txhim kho cov nplaim hluav taws xob thiab cuam tshuam lub zog ntawm PVC.
